Developing Simulated Learning Experiences

I'm writing my first scripts for student roles (family members, etc.) for use during simulations, any tips or tricks? Do I give specific lines they should say or a general idea of their role and questions to ask?

You are more likely to have a successful simulation if you are specific in your instructions on how to portray each role. Your simulation should be designed with specific objectives in mind. Each person who participates should contribute to meeting those objectives. A confederate who improvises too much can inadvertently lead the student(s) in the role(s) of "nurse" down an unintended path. If you are using the role to provide cues to students if /when they need them, be specific about when and under what conditions the cue is offered.